Hi I have a 1987 F700 with the ford 370 gas engine in it and I'm trying to find the engine hp and torque rating on it.

In the owners manual it just lists the specs for the 2 Ford diesels also offered back in 1987 nothing about the Gas engines! Even in my Ford shop service manual it only lists performances specs for the darn diesels!

I'm replacing this truck with a new one and I want to be sure I'm going big enough with the new diesel engine. It comes with the 6.7 ICB cummins 300hp @ 2600rpm and 620lbs torque at 1600 rpm.

I have it geared so that it should do 62mph at 2000 rpm.

The old 370 was under powered for the job it had to do so I just want to be sure this new engine will end my under power issues!

Its been suggested that the 370 in that year might be around 190-200hp??

I say if the old 370 Gas burner was enough to Actually DO the job (doesn't mean it had to do it well) that the 300 HP ISB would work GREAT. 300 Hp is near the upper limits of HP your going to find in an MDT.

I don't know what transmission you spec ed but i think that 62 Mph at 2000 Rpm might be too short a gear. 4.56?

What are you expecting this truck to do? Grain wagon?

Any more HP your going to need to step up into a larger Vocational or over the road truck.

Well the truck is coming with the Fuller 6 speed overdrive trans and a rear axel ratio of 4.88. The salesmen says it should do 63mph(to be exact) at 2000rpm going by his scale. At 2400 rpm is suppost do 74.5 mph and in 5th at 2400rpm it should do 59mph. I thought of 4.11 with the overdrive but then I think it drops it to 1800 or so. If I have plenty of power that might work fine. But if I need more power then I'm shifting down. 6th is overdrive and 5th gear would be direct drive.

I'm not sure what would be the "best" ratio as I can't actually try this truck out with my set up on the back before I get it. Most manufactures seem to bring them in with the 6 speed and the 3.90 rear ends or 4.11's. Or if they are using the overdrive 6 speed the 4.88 or 5.29 ratio. As these little single axels typically have van bodies put on the back. So they are bucking a fair bit of wind as they are tall. Sort of like what this truck will be doing moving hay stacks of square bales. It won't be loaded up on wieght too much but will have to buck some wind. Thats what gave the old 370 trouble. On a flat ground and no wind it could run at 55mph no problem. Throw in a bit of head wind or a little hill and look out you were shifting into forth and burning fuel big time. That was another problem when it was on the highway it was geared so low at 55-60 it was screaming at 3500 rpm. running empty Loaded I always had the pedal down lugging it at 2500-3000.

A lower numerical axle ratio like the 4.88 may be required to get the lowered speeds You need for running around the fields loaded. The 6.7 should be a BIG improvement over the 370 Ford. You didn't say what axle ratio or type the 370 Ford had but I would assume a 2-speed...You may want to consider the 2-speed, if they even make them anymore, or a Lo-Hole transmission. If Your loading on a solid surface or near a road it may not be an issue.

I would guess the 370 in '87 was only rated 150-160 hp...Maybe 170 but I'd be surprised. As long as You have low enough gears for the slow work &amp; hard pulls I think the 300 HP 6.7 should make Your new truck a lot faster... The semi I used to drive had a 320 HP Cummins 903 and it was geared to run 67 mph @ 2500 w/rated HP @ 2600...and I could run 67 mph all day at 70,000-75,000# gross.

If your cruise MPH is 65, you want to gear so the engine is turning 2150-2250 rpm. This is directly from Cummins website for the ISB 5.9. There wasn't info for the 6.7 but it should be about the same. It also states a minimum of 1900 rpm so it sounds like you are geared pretty good from your opening post. I used all highway for the example. You can go play with it here.www.powerspec.cummins.com/

Well I put in all my info regarding wieght and type of truck best I could. So If you go by what they say for the 5.9 ICB I'm right on the low side for RPMs at cruise speed but still with in the range they allow. But like you say they recomend 2150 rpm.

Going by my trans, diff, tires, it should do 62mph (100kms) at 1951 rpm. Or 68mph (110kph) at 2140. My local highways are typically 100 or 110 kms per hr.

Now I don't know what the ICB is governed at this 6.7 ICB is governed at 2600rpm.

I'm not too sure now I got it speced right. All depends on how this 6.7 handles the load. I wish they had the new 6.7 a person could plug in there and see how it comes out.

50% of the time this truck runs empty with no load on the back. So that would be no hay sticking above the cab to buck wind like a van body. So thats why I figured it was geared pretty close.

I don't know what the terrain is like where you are but I would look for more speeds than 6 if available. I think 2 speed rears are still made if you can't find a 7 speed or better transmission. My choice would be a 10 speed if it is economical in something that small. A 5 speed with 2 speed would be almost as good.

If it is flat and you don't lose too much speed between gears, though, the 6 speed might do all right. But these modern diesels still have a somewhat limited rev range.

You can get 9-10 speeds in these little trucks. But typically they come in with an auto or 6 speed it seems. I had the split rear axel on the old F700 but really I never used it on the road. I did use it for a slower reverse sometimes though. My roads here are pretty flat and with the extra power I just figured a 6 speed geared for the highway would work ok.

The engine should be almost the same for power as the 5.9 ISB on the Powerspec tool. I could see there being a difference if you had the highest rated 6.7 but the previous 5.9 was rated close to your specs. If you want, play with the tool and put in your info with the ISC engine that is 8.3L. The RPM should be pretty close or you can split the difference.

I believe the older ones were rated at 160hp with a 4bbl. They really aren't a bad motor, we have one in a old fuel truck, with a 5/2 combo. It will actualy run 70mph all day long(4000rpm) with a full load of 2000 gallons(around 30K gross). personaly, I think it has more power than our kodiak with a 3116 cat, of course our DT466 trucks blow the doors off both though..
Of course if you realy wanna talk about what a 370 will do.. way back in the day we had a cabover tractor with a 370, backed by a 5x4. I recall riding in it as a kid with the lowboy and our D9 on the back... :O

Register Now

In order to be able to post messages on the Diesel Forum - TheDieselStop.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:

Password

Please enter a password for your user account. Note that passwords are case-sensitive.

Password:

Confirm Password:

Email Address

Please enter a valid email address for yourself.

Email Address:

OR

Log-in

User Name

Password

Remember Me?

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.